'use strict';
var single_element = function(collection){
    let arrEven=[],res=[];
    for(let i=0;i<collection.length;i++){
        if(i%2!==0){
             arrEven.push(collection[i]);
        }
    }
    
    function norepeat(a) { 
        var i = a.length, j, b; 
        while (i--) { 
            j = i; 
            b = false; 
            while (j--) { 
                if (a[i] === a[j]) { 
                    a.splice(j, 1); 
                    i--; 
                    b = true; 
                } 
            } 
            if (b) a.splice(i, 1); 
        } 
        console.log(a);
        return a; 
    } 
    return norepeat(arrEven);
};
module.exports = single_element;
